Climate change outlook clarified
New study says very large warming 'unlikely'
A new dataset revealed today bolsters the scientific consensus on the effect of greenhouse gas emissions.
A reconstruction of the Northern Hemisphere's climate over the past 700 years appearing in Nature suggests global temperatures are more robust than some reports previously indicated.
"Climate sensitivity" is a defined measure of how the climate behaves when the level of carbon dioxide is doubled. Some previous estimates had predicted the temperature could rise by as much as 9°C.
Some hardcore statistical work by a transatlantic team at Duke and Oxford universities states that anything much higher than 6.2°C is highly unlikely. The accepted likely broad range is 1.5°C to 4.5°C.
Crucially, the level of climate sensitivity they got from reconstructions based on tree rings and other data was totally consistent with the estimates made from direct temperature observations in the 19th and 20th centuries.
The work should buttress the scientific foundation available to policymakers when making the case for tackling carbon emisssions.®